Various lectures on ESSO, Gulf Oil and Shell activities by F. E. Bleasdale, Geoffrey Owen, Jerry McAfee, and Dr. J. F. Fortuin, Box: 14, Folder: 56. Charles Heller papers, RH MS 314. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/490247 Accessed May 06, 2024.